1. Field of the Invention
This invention relates generally to piconet wireless networks. More particularly, it relates to a more secure pairing process in a piconet network such as a BLUETOOTH™ type piconet network.
2. Background
Piconets, or small wireless networks, are being formed by more and more devices in many homes and offices. In particular, a popular piconet standard is commonly referred to as a BLUETOOTH™ piconet. Piconet technology in general, and BLUETOOTH technology in particular, provides peer-to-peer communications over short distances.
The wireless frequency of the piconets may be 2.4 GHz as per BLUETOOTH standards, and/or typically have a 20 to 1000 foot range. The piconet RF transmitter may operate in common frequencies which do not necessarily require a license from the regulating government authorities, e.g., the Federal Communications Commission (FCC) in the United States. Alternatively, the wireless communication can be accomplished with infrared (IR) transmitters and receivers, but this is less preferable because of the directional and visual problems often associated with IR systems.
A plurality of piconet networks may be interconnected through a scatternet connection, in accordance with BLUETOOTH™ protocols BLUETOOTH network technology may be utilized to implement a wireless piconet network connection (including scatternet). The BLUETOOTH standard for wireless piconet networks is well known, and is available from many sources, e.g., from the web site www.bluetooth.com.
Conventionally, analog headsets were used with wireless phones. Analog headsets are wired directly into the audio path of wireless phone. However, more recently, BLUETOOTH technology has permitted the addition of BLUETOOTH functionality and communication between a wireless phone and a wireless headset.
The Headset Profile of the BLUETOOTH specification, version 1.1, Part K:6, available at www.bluetooth.com, provides the framework for conventional BLUETOOTH communications between a wireless BLUETOOTH phone and a wireless BLUETOOTH headset.
FIG. 4 shows the protocols and entities regarding how a BLUETOOTH headset interacts with a wireless BLUETOOTH phone acting as an audio gateway to provide a wireless hands free connection for a wireless phone (e.g., a cell phone).
In particular, FIG. 4 shows the protocol model of both an audio gateway 502 and a BLUETOOTH headset 504. “Audio gateway” refers to a wireless BLUETOOTH phone 502 in the given example. The audio gateway 502 is the gateway for both input audio and output audio. The BLUETOOTH headset is the device which acts as the audio gateway's remote audio input and output mechanism.
The baseband 524, 534, LMP 522, 536 and L2CAP 528, 532 are the OSI layer 1 and 2 BLUETOOTH protocols. RFCOMM 520, 538 is the BLUETOOTH adaptation of GSM TS 07.10. SDP 526, 530 is the BLUETOOTH service discovery protocol.
Headset control 512, 516 is the entity responsible for headset specific control signaling. The headset specific control signaling is AT command based.
The audio port emulation application layer 510 in the wireless BLUETOOTH phone 502 is the entity which emulates the audio port on the wireless phone, and the audio driver application 514 is the driver software in the BLUETOOTH headset 504.
The audio gateway 502 and BLUETOOTH headset 504 provide serial port emulation. For the serial port emulation, RFCOMM 520, 538 is used. The serial port emulation is used to transport the user data including modem control signals and AT commands from the BLUETOOTH headset 504 to the audio gateway 502. AT commands are parsed by the audio gateway 502 and responses are sent to the BLUETOOTH headset 504.
The Headset Profile requires mandatory control requirements for a BLUETOOTH headset audio gateway. FIG. 5 depicts the conventional establishment of a connection with respect to an incoming call.
In particular, as shown in step 602 of FIG. 5, the wireless BLUETOOTH phone 502 initiates connection establishment with the BLUETOOTH headset 504.
In step 604, once the connection is established between the wireless BLUETOOTH phone 502 and the BLUETOOTH headset 504, the wireless BLUETOOTH phone 502 sends an unsolicited result code RING to alert the user of the BLUETOOTH headset 504. Optionally, the wireless BLUETOOTH phone 502 may provide an in-band ringing tone as shown in step 608 (which would then be sent after step 606). The ring signal may be repeated as depicted in steps 610, 612 for as long as the connection establishment is pending.
In step 606, SCO link establishment is initiated by the wireless BLUETOOTH phone 502.
In step 614, the user may accept the incoming audio connection by pressing a button on the BLUETOOTH headset 504. When the user accepts the incoming call, the BLUETOOTH headset 504 will send an AT+CKPD command to the wireless BLUETOOTH phone 502.
In step 616, the wireless BLUETOOTH phone 502 sends an OK acknowledgement back to the BLUETOOTH headset 504.
In step 618, the wireless BLUETOOTH phone 502 establishes the SCO link (if not established earlier in step 606).
Thus, the BLUETOOTH specification as defined by the BLUETOOTH special interest group (SIG) requires certain control information (e.g., relating to onhook, offhook, etc.) to be communicated in a digital path from a wireless BLUETOOTH phone 502, forcing the wireless BLUETOOTH phone (or other device) to have a priori knowledge of the existence of BLUETOOTH in the device.
This means that for most wireless phones, adding the ability to communicate with a BLUETOOTH headset requires integrating a BLUETOOTH stack into the wireless phone.
Some wireless phones (e.g., the model T28 commercially available from ERICSSON™) have a complex interface that allows the after-manufacture addition of a BLUETOOTH communication module without requiring updates to the software in the wireless phone. However, most conventional wireless phones do not have such a sophisticated interface.
Moreover, commercially available headsets for most older wireless phones are not wireless. Rather, these conventional wireless phones merely have a jack allowing the addition of only a wired headset. As an example, the model 5160 commercially available from NOKIA™ may include a wired headset that includes a button to answer an incoming call.
There is a need for apparatus and methods which allow a BLUETOOTH headset to communicate with an otherwise conventional wireless phone, without requiring the use of a wireless BLUETOOTH phone already including a BLUETOOTH communication module. This would provide users of older wireless phones the ability to use a wireless headset by allowing a BLUETOOTH headset to be used with non-BLUETOOTH enabled wireless phones.